Ideally, we should become cross-trained "experts" as has been
suggested in this case.  The real world demands otherwise.  I was
trained in anthropology with an archaeology/prehistory emphasis,
geographically in North America.  To do this better I was fortunate
to study lithic technology with Don Crabtree.  My first opportunity
to apply this acquired skill came from Middle American Archaeologists.
 While I didn't know a model carved polychrome from a cenote when I
arrived in Yucatan, I like to think I made a significant contribution
as the result of a successful collaboration.  And I did learn, at
least, what a cenote is, but there's still a world of ignorance on my
part about polychrome pottery that I will never overcome.  Obviously
I refrain from doing ceramic analysis of any kind, but should I have
disqualified myself and declined the invitation?
 
I also have moved into the phantasmagoric world of plant
microfossils.  I am not an "expert" botanist or microscopist, etc.,
but here again I hope I am making a significant contribution.  Even
within the limits of collaborations with archaeologists, I am now
working on prehistoric and historic period sites as well as some
purely paleoecological projects.  I've got dirt from South Carolina
Plantations, Paleoindian Bison Teeth from the Plains, Central and
Eastern European dirt and animal teeth dating from Neolithic to
Medieval times, Pleistocene loess from China, Miocene sediment from
South America, prehistoric polynesian samples, southern Sahara
Pleistocene sediments, etc.  If I must become fully informed of the
context in which the data I generate will be interpreted - however
desirable that might be theoretically, I would never get started
doing anything for want of having to become the global expert on
everything.  As I recall, the only person qualified to do this was an
old vaudvillean who made it to TV named Professor Irwin Corey, the
World's Greatest Expert.  If you remember him, he may in fact
represent an appropriate model of the ideal scientist for many of us.
 
Irv Rovner
Binary Analytical Consultants